2 INTRODUCTIONLCH: heterogeneousease, characterized by accumulation of dendritic cells with futures similar to epidermal Langerhans cells in various organs.Any organ or system of the human body can be affectedthoseskeleton (80%)skin (33%)pituitary (25%)Other organs involved are the liver, spleen, the hematopoietic system and the lungs (15% each)lymph nodes (5–10%)CNS excluding the pituitary (2–4%)

3 INTRODUCTIONThe clinical course may vary from a self- limiting disease to a rapidly progressive one that might lead to death.Between 30% and 40% of patients may develop permanent adverse sequelae.Treatment options vary depending on the extent of the disease and the severity at onset.

4 INTRODUCTIONguidance with respect to diagnosis and clinical work-up of LCH occurring in patients <18 years old.The recommendations can neither replace the physician’s own professional judgement nor consider all special clinical circumstances which may apply to individual cases.The guidelines were designed and established by European and North American physicians considered to be experts in the ﬁeld of pediatric histiocytic disorders.

5 Evidence was ranked in four levels(A) meta-analyses, high quality systematic reviews, or randomized controlled trials with a low risk of bias;(B) systematic reviews of case–control or cohort studies;(C) non-analytic studies; for example, case reports, case series, small retrospective studies(D) expert opinion.Level of agreement between experts and data was ranked in three classes:general agreement between all experts or between available studies;discussed recommendation, but no formal objections between experts or mild difference between studies, without contradiction for the main endpoint;divergence of opinion or contradictory results for the main endpoint.

10 LCH -DiagnosisHistologically characteristic appearance of the LCH lesions on hematoxylin and eosin stained sections.But: positive CD1a and/or CD207 (Langerin) staining of the lesional cells is required for a deﬁnitive diagnosis.Electron microscopy is no longer needed, since it has been shown that the expression of Langerin correlates with the ultrastructural presence of Birbeck granules .Diagnostic conﬁrmation may be a challenge in some circumstances (e.g., liver specimens):where Birbeck granules are not present and CD1a and/or Langerin may be negative because ;LCH cells have regressed after having caused sclerosing cholangitis and Cirrhosis

11 LCH -DiagnosisIn rare cases the risk of biopsy may outweigh the need for a deﬁnitive diagnosis, and therefore the risk/beneﬁt ratio should be carefully assessed:patients with isolated involvement of a vertebral body without an adjacent soft tissue component, as in case of vertebra plana, .If the decision to avoid :rule out other conditions that might lead to a similar radiological ﬁnding

12 LCH -DiagnosisPatients without a histologically conﬁrmed diagnosis need to be carefully monitored by appropriate imaging for at least the next 6 months in order to reassess the need for biopsy and its justiﬁcation, in order to exclude a malignancy.

18 Exposes the patient to a signiﬁcant radiation dose Defining Organ Involvement, Risk Organs, and CNS (Central Nervous System) Risk LesionsPET scan has proven to be the most sensitive functional test used in the identiﬁcation of LCH lesions and in evaluating patient response to therapy ,However:ExpensiveExposes the patient to a signiﬁcant radiation doseIs not widely available.It is not recommended to change the method of bone evaluation (skeletal radiograph), as it may lead to discrepancy between assessments.

19 Defining Organ Involvement, Risk Organs, and CNS (Central Nervous System) Risk LesionsAbsence of involvement of other risk organs, lung disease is only in exceptional cases the ultimate cause of death and this usually occurs through ‘‘mechanical complications’’ such as an uncontrolled pneumothorax or as a late event due to chronic emphysematous changes.In the upcoming clinical trial for LCH in children (LCH-IV), the lung will be no longer considered a risk organ.

20 Defining Organ Involvement, Risk Organs, and CNS (Central Nervous System) Risk LesionsInvolvement of some skull bones might predispose to diabetes insipidus (DI) and CNS manifestationsThe term CNS risk lesions, representing a more recent concept ,suggests that these patients are more likely to develop neuro- degenerative CNS disease, which may be an irreversible complication of LCH and may have a debilitating course

21 Clinical Classification-LCHSingle system disease (SS-LCH)Multisystem disease (MS-LCH),In SS-LCH, only one organ or system is involved such as bone (either as a single bone or more than one bone), skin, lymph node (not the draining lymph node of another LCH lesion), lungs, hypothalamic-pituitary/central nervous system, or others such as thyroid or thymus.In MS-LCH, two or more organs, or systems are involved either with or without involvement of risk organs.

23 Langerhans cells histiocytosis killed my lovely babyMy daughter was a healthy baby, the symptoms of this disease started when she was about 6 months. But we thought all those were normal. Scalp problem, itchy. Fever and diarrhea, was due to her growing teeth.We went to see doctors for many times, but couldn't solve her problems.One of the doctor wrote a letter for us, he suggested us to send her to hospital for a check- up. After 3 months, the specialist told us she diagnosed with LCH, a very rare disease.

24 Langerhans cells histiocytosis killed my lovely babyHer chances to be cured was 50%.I searched a lot from the internet, i knew what it is, some of the websites say the outcome for the patients of LCH, who are below 2 years old are poor. That means, no one survive When she was undergoing the chemotherapy, i hadn't never tell my parents about that, i was hoping she'd get well, and be the lucky one who survive from this illness!!!!But.... She'd gone after about 9 months of treatments I feel so regret, guilty She was such a lovely, smart, girl.Though she was only 22-month!!! She understood what we said, she was so sweet to make me smile when i was angry even she was sick, and pain...I'm so sorry, baby... I'm not a good mummy... I'll repay you in my next life!!!!!!!!!!!

45 Central Diabetes Insipidus as Presenting Symptom of LCH. Helmut proschCentral Diabetes Insipidus as Presenting Symptom of LCH . Helmut prosch. .Pediatric Blood and cancer 2004If the search for extracranial lesions was not successful in a CDI patient, we consider a lumbar puncture indicated. CSF should be analyzed for CD1a positive cells in the cytospin and for tumor markers .associated with secreting germ cell tumor

46 Treatment of single-system LCHPatients with SS-LCH may be initially referred to a range of medical specialists depending on the localization and presentation of the lesions, thus it is difﬁcult to organize and execute coordinated international trials.This section combines the limited published evidence with the authors’ experience (evidence: C, agreement: 1).

47 Treatment of single-system LCHSingle system unifocal bone involvement (isolated bone lesions).Unifocal bone lesions are the predominant clinical form of LCH.Spontaneous regression , and the clinical course is probably not greatly inﬂuenced by any form of treatment.

48 Treatment of single-system LCHThe decision on the most appropriate approach should be based on clinical symptoms, the size and location of the disease, and on any evidence of healing on imaging.Often:simple curettage during the diagnostic biopsy will result in healing, and further intervention may not be necessaryIndications for additional treatment include :Involvement of weight-bearing bonesImminent spinal cord compressionUnacceptable deformityIntense painFunctional disability.

49 General Considerations for TreatmentComplete excision of bone lesions (curettage) :if the lesion is small (<2 cm) and is combined with the diagnostic conﬁrmation.Radical excision of large lesions (>5 cm) is not indicated since it increases the size of the bony defect, could prolong the time to healing, and might result in permanent skeletal defects.For lesions 2–5 cms in diameter, a biopsy and partial curettage is an option.Depending on the size and location of the lesion, an intralesional injection of methylprednisolone may be administered to promote healing (evidence: C).Immobilization of the limb may need to be considered and discussed with the orthopedic surgeon in rare cases.

50 General Considerations for Treatment‘‘Vertebra plana’’ per se is not an indication for an orthopedic corset, and expert physiotherapy assessment should be considered; however, temporary immobilization may be required for symptomatic relief in the early phases of vertebral involvement.Patients with temporal bone lesions and recurrent otorrhea, may have a secondary cholesteatoma which may need speciﬁc treatment.

51 General Considerations for TreatmentIn certain functionally critical anatomical sites: (vertebral lesions with intra-spinal soft tissue) however, these are exceptional situations, and a biopsy should always be considered.Because of the potential for development of sequelae, systemic therapy is indicated in patients with lesions involving the skull base, temporal bone, orbits, and vertebral column, where there is also involvement of the adjacent soft tissues.

52 Single system -Multifocal bone involvement(SS-LCH multifocal bone) usually remains conﬁned to the skeleton, and only rarely extends to other organs like the skin and pituitary gland.Incidence of reported reactivations in cases of multifocal bone disease is higher than for unifocal bone disease .Regardless of the treatment approaches that vary from observation only to systemic chemotherapy survival rates approaching 100% are reported for this disease form in almost all the published series.The most commonly used therapy for multifocal skeletal LCH consists of steroids and vinblastine (VBL),

53 Single system skin involvement (isolated cutaneous LCH).Rare -about 5% of the LCHAny age, but is most common in newborns and infants.Most regress spontaneously, but progression to MS-LCH is common. Therefore, close follow-up in all young patients with this disease form.Isolated nodules or as a skin rash; in patients with isolated nodules surgical excision may be indicated, but radical surgery is never warranted.Topical steroids, but their efﬁcacy has never been proven.Moreover, most patients with isolated cutaneous LCH are often diagnosed after unsuccessful treatment with topical steroids for other presumed diagnoses such as eczema

54 Single system skin involvement (isolated cutaneous LCH)In cases of ineffective local therapy or involvement of an extensive area: systemic therapy with steroids (VBL), or oral low dose MTX ,but the level of evidence is low (D)Most severe cases, : thalidomide associated with neurological toxicity, pain and fatigue ,azathioprine, or PUVA-therapy which have been shown to be effective in some adult patients, might also be considered in children (evidence: D, agreement: 1)

55 Single System LCH-Lung (primary pulmonary LCH).predominantly in adolescent and adult smokers.The impact of systemic therapy is not well documented in children, and adult pulmonologists do not consider it as the standard approachSmoking withdrawal is necessary, and usually results in signiﬁcant clinical improvement and often complete resolution.Risk of acute severe complications such as pneumothorax, or cardiopulmonary arrest.

56 Single System LCH-Lung (primary pulmonary LCH).Pneumothoraces should be treated by standard techniques such as drainage and possibly pleurodesis.Pleurectomy should be avoided as lung transplantation may ultimately be considered in patients with severe progressive disease.In case of persisting and progressive lung disease, systemic therapy with low dose steroids is most commonly used, but 2- chlorodeoxyadenosine (2-CdA), and the combination of VBL and steroids have also been used (evidence: D, agreement: 1).

57 Single System LCH- diabetes insipidus /DIIsolated diabetes insipidus and pituitary involvement.DI occurs due to involvement of the posterior pituitary (neurohypophysis) and may become manifest either before, concurrently, or after LCH diagnosis.Isolated DI is not considered an indication for systemic therapy per se, except when active disease is unequivocally documented by the presence of thickening of the pituitary stalk or a mass lesion of the hypothalamic-pituitary axis.A lesion of the hypothalamus–pituitary axis is usually considered as active if it had local neurological consequences like alteration of the visual ﬁeld or if its volume is increasing on sequential MRI.In the experience of experts, DI is with few exceptions uniformly irreversible, although DDAVP needs may vary.Some reports ; 2-CdA, VP16, or radiation soon after DI onset may reverse the condition (evidence: D).

58 LCH-Brain LesionsBrain lesions, In addition to pituitary stalk lesions, any brain, or meningeal lesion is considered an indication for systemic therapy.The standard therapy with vinblastine and steroid can be effective in this situation or 2-CDA monotherapy

59 Treatment of multisystem LCHPatients with risk organ involvement are at risk of death, and a poor response to therapy deﬁnes a subgroup with a particularly dismal prognosis.Patients without involvement of risk organs, although not at risk for mortality, need systemic therapy in order to control the disease activity, reduce reactivations, and reduce permanent consequences.Several international protocols for MS-LCH treatment have been designed within the framework of the HSTheir main conclusions are (evidence: B, agreement: 2)(i) standard treatment is based on steroids and VBL,(ii) Clinical response after the ﬁrst 6 weeks of treatment is a good marker of further disease evolution.(iii) Prolonged treatment for at least 1 year reduces the risk of disease reactivations.

60 Front Line Treatment and Evaluation of ResponseAssociation of VBL 6 mg/m 2 i.v. weekly bolus for 6 weeks, with prednisone 40 mg/m 2 /day given orally in three divided doses for 4 weeks and then tapered over the following 2 weeks.After the ﬁrst 6 weeks of treatment, disease status should be reevaluated and treatment continued accordingly.The evaluation of the disease response is usually classiﬁed as ‘‘Better’’ in case of complete resolution or regression of the disease,‘‘Worse’’ in case of progression of the disease,‘‘Intermediate,’’ in case of stable or mixed response with new lesions in one site, and regression in another site.

61 Treatment of multisystem LCHIn case of a good response (especially in the risk organs) but with some active disease still present in other sites, treatment with VBL, and steroids should be continued for another 6 weeks with: VBL 6 mg/m 2 i.v. weekly bolus, and prednisone 40 mg/m 2/day orally in 3 divided doses for 3 days every week.1 or 2 intensive courses according to the above mentioned schedule should be followed by maintenance therapy for a total duration of up to 12 months with VBL 6 mg/m 2 i.v. bolus every 3 weeks, and prednisone 40 mg/m 2/day orally in three divided doses for 5 days every 3 weeks and 6 MP at a dose of 50 mg/m2 /day is added if risk organ involvement is present.

62 Second Line Therapy MS-LCHRefractory disease in patients with hematological involvement or liver dysfunction is a rare but life- threatening situationTherapeutic options (evidence: C) include combination chemotherapy with cladribine (2-CdA) and cytarabine (Ara-C) or hematopoietic stem cell transplantation using reduced intensity conditioning regimen.If there is evidence of disease progression in ‘‘non-risk organs,’’ treatment with 2-CdA as monotherapy [41] or even with further courses of a combination of VBL and steroids should be considered.

66 RadiotherapyMost experts in this ﬁeld would no longer recommend radiotherapy due to the risk of long term sequelae, including the potential risk of developing a malignant tumor in the ﬁeld of the radiotherapyHowever, there are some physicians who consider that radiotherapy may be useful for a single bone lesion in teenager (evidence: C, agreement: 2).

67 Neurodegenerative Complicationsneed to be managed by a multidisciplinary team.Several therapies have been attempted but with possibly occasional transitory responses.The treatment options include: retinoic acid ,combination treatment with vincristine and Ara-C ,IVIG ,cladribineTo date, intensive therapies have not shown any effect and should thus be avoided, especially as they may add to the morbidity.

68 Monitoring and Supportive Care for Permanent ConsequencesSome may be present at diagnosis, while others may become manifest up to years and decades later.monitor these patients at least until growth is completed and possibly into adult life.The most common permanent consequences :Endocrine,Auditory,Orthopedic.Neurocognitive, pulmonary, and hepatic sequelae are rare but may cause signiﬁcant morbidity.

69 Monitoring and Supportive Care for Permanent ConsequencesEndocrine complications. DI is the most frequent /15% to 30% of casesEven many years after the diagnosis of LCH.GH deﬁciency is the most frequent anterior pituitary hormone loss /10% of patients.Height and weight & assessment of puberty /every 6 months or 1 year until growth is completed.Any child whose growth is below that expected may need to be investigated as suggested by the consensus guidelines of the GH Research SocietyOther hormone :delayed puberty and rarely panhypopituitarism.

71 Orthopedic.When several vertebrae are affected, scoliosis may become manifest later in life, in particular during periods of rapid growth such as puberty.Children should be assessed clinically at least annually in order to identify any early signs of scoliosis.They should be referred to the orthopedic surgeon in order to start preventive physical therapies (e.g., orthopedic corset/brace or neck collar) in order to manage this proactively.If facial bones are affected, facial asymmetry may become manifest and reconstructive surgery may be required.

72 HearingSubjects with involvement of the middle or inner ear and the temporal bone should be monitored with audiometry at diagnosis and at end of treatment and reassessed at start of school and if any new symptoms develop.Early diagnosis and interventional strategies such as hearing aids can avoid deterioration of school performance and signiﬁcantly improve learning

73 Oral tissue and jawChildren with involvement of gums and jaw should be monitored for dental development and growth of the jaw.Neurological:Children with multisystem LCH should be regularly followed up clinically since they are at risk of developing late neuropsychological sequelae, in particular cerebellar ataxia and learning difﬁculties.In children with relevant history and/or abnormal neurological examination, further investigations including neuropsychological tests, cerebellar function assessment - MRI of the head should be performed.

74 LUNGSIn those with a history of lung involvement, spirometry should be performed regularly and if abnormal or progressive, X-ray and CT of chest may be needed.The dangers of smoking should be explained and smoking avoided.Pulmonary involvement may also lead to respiratory insufﬁciency due to ﬁbrosis and emphysema.Liver:with abnormal liver function consider ultrasound scan, MRI of liver, or cholangiography as clinically indicated.A subset of young children with liver involvement may subsequently develop sclerosing cholangitis that progresses to cirrhosis; treatment for these children includes liver transplantation.

75 Associated MalignanciesThere is a recognized association between LCH and malignancies .The malignancies may precede, occur concurrently or follow the diagnosis of LCH and should be considered at every clinical visit.

76 Follow the diagnosis of LCHALL and lymphoma more often occur prior to the diagnosis of LCH but may be diagnosed within 5 years after LCH.AML usually follow LCH especially in those patients exposed to etoposide, alkylating agents and/or radiotherapy.Solid tumors may occur concurrently or follow the diagnosis of LCH. Most of those that followed LCH developed in a previous radiation ﬁeld.With the current treatment strategies it is expected that these types of secondary malignancy will be rare.Patients treated with radiotherapy should see their doctor in case of symptoms involving the irradiated area.

77 Follow-Up/Duration and FrequencyEvery patient should be followed by the local physician and if at any time a particular issue needs to be addressed, referral to a specialist is recommended.All patients should be followed for a sufﬁcient time period, deﬁned as(i) at least 5 years after the end of therapy; or(ii) 5 years after the last disease reactivation, in those who did not receive systemic therapy;or(iii) until ﬁnal growth and pubertal development have occurred

78 LCH’s etiology is unknown. Recurrent BRAF mutations in Langerhans cell histiocytosis Gayane Badalian-Very.Blood 2010LCH’s etiology is unknown.The benign morphology of its proliferating cells and its characteristic inﬂammatory inﬁltrates suggest that LCH may be an inﬂammatory disorder,and dysregulated expression of inﬂammatory cytokines, such as interleukin-17A, has been reported.However, the pathologic Langerhans cells (LCs) in LCH are clonal.Although clonality is an important feature of neoplasia, recurrent genomic abnormalities would be required to demonstrate that LCH is a neoplasm; and, to date, none has been reported.

79 Perspectives.In 2010, Badalian-Very et al. reported somatic mutations of the BRAF oncogene in about half of the LCH patients in their series, and this ﬁnding was recently conﬁrmed by other teams .This discovery may have a signiﬁcant potential impact if we consider the possibility of treating LCH with the new class of BRAF inhibitors.However, this promising discovery will need to be veriﬁed and concretized before these drugs can be used for treatment of LCH.The group(s) of LCH patients who may beneﬁt from BRAF inhibitor treatment must be determined and balanced with toxicities as in the case of melanomaKnowledge about drug schedule and safety, especially long-term effects and mechanisms of resistance must be acquired

80 Recurrent BRAF mutations in Langerhans cell histiocytosis Gayane Badalian-Very.Blood 2010LCH has a broad spectrum of clinical behaviors; some cases are self- limited, whereas others involve multiple organs and cause signiﬁcant mortality.Although Langerhans cells in LCH are clonal, their benign morphology and their lack (to date) of reported recurrent genomic abnormalities have suggested that LCH may not be a neoplasm.Here, using 2 orthogonal technologies for detecting cancer-associated mutations in formalin-ﬁxed, parafﬁn-embedded material, we identiﬁed the oncogenic BRAF V600E mutation in 35 of 61 archived specimens (57%).TP53 and MET mutations were also observed in one sample each.BRAF V600E tended to appear in younger patients but was not associated with disease site or stage.Langerhans cells stained for phosphomitogen–activated protein kinase kinase (phospho-MEK) and phospho-extracellular signal-regulated kinase (phospho-ERK) regardless of mutation status.High prevalence, recurrent BRAF mutations in LCH indicate that it is a neoplastic disease that may respond to RAF pathway inhibitors.

81 2007.Pediatric Transplantation Successful treatment of refractory Langerhans cell histiocytosis by allogeneic peripheral blood stem cell transplantationAbstract:We describe a 6-yr-old boy who exhibited typical signs and symptoms of LCH with EBV-associated hemophagocytic syndrome from the age of 15 months.Multiple courses of conventional chemotherapy achieved only marginal improvement over the ensuring five yr.During this period, this boy experienced recurrent episodes of hemophagocytic syndrome associated with CMV infection. Five yr after the first diagnosis of LCH, the patient was treated with allogeneic PBSCT from his HLA- identical eight-yr-old brother. PBSCT was performed using a TBI-incorporating conditioning regimen comprising TBI, busulfan, and cyclophosphamide.Diabetes insipidus, typically a permanent consequence of LCH, was well controlled by DDAVP therapy.At the time of writing, this boy is alive and well, and had been disease-free for more than two yr after the PBSCT

82 The median age at SCT was 23 months (range, 13– 178 months).Bone Marrow Transplantation Improved outcome of refractory Langerhans cell histiocytosis in children with hematopoietic stem cell transplantation in JapanHematopoietic stem cell transplanta tion (SCT) is a promising approach for refractory LCH because of its immunomodulatory effect.In this study, the outcomes of children with refractory LCH undergoing SCT in Japan were analyzed.Between November 1995 and March 2007, 15 children younger than 15 years (9 males, 6 females) with refractory LCH underwent SCT. The patients’ median age at diagnosis was 8 months (range, 28 days to 28 months), and all had failed conventional chemotherapy.The median age at SCT was 23 months (range, 13– 178 months).

83 Bone Marrow Transplantation 2010Bone Marrow Transplantation Improved outcome of refractory Langerhans cell histiocytosis in children with hematopoietic stem cell transplantation in JapanNine had risk organ involvement at diagnosis, including liver (n=6), spleen (n=5), lung (n=5), and/or hematopoietic system (n=4).For SCT, a myeloablative regimen was used for 10 patients, and a reduced-intensity conditioning regimen (RIC) was used for five.The donor source varied among the patients, but allogeneic cord blood was primarily used (n=10).Subsequently, 11 of 15 patients have survived with no evidence of disease, with a 10-year overall survival (OS) rate (median±standard error) of 73.3±11.4%.The 10-year OS rate of nine patients with risk organ involvement at diagnosis was 55.6±16.6%, whereas six without risk organ involvement have all survived with no evidence of disease (P=0.07).These results indicate that SCT is promising as a salvage approach for children with refractory LCH